Trust is doubtless reliance on character, ability, strength or truth of someone or something. Before opting the services of any Cloud Service Provider (CSP) there is a need to evaluate trustworthiness of various CSPs available in market. Consumer or user should cherry-pick the CSPs collection. However, determining the trust and selecting best service provider according to users’ own requirements is an arduous task. This paper represents various trust evaluation models that are available in literature. User can establish trust with the help of any one of these models. But there is no universally accepted model. Since trust is an idiomatic term, evaluating trust remains a major issue while making headway towards Cloud Computing.